The now global diffusion of large-scale distribution has produced an ancillary industry, linked to packaging techniques, in which even small improvements in the production and operation of the devices used bring significant economic benefits, due to the “big numbers” in this sector.
In particular, in the wrapping of pallets (understood to be a stacked set of packaging units, for example crates) using plastic films, rotary platforms are often used, onto which the pallet must first be lifted, before its movement can be started. The platforms currently used are several centimeters thick (usually between 5 and 10) and therefore have up ramps which, due to the mass of the pallet, make the moment it is loaded on the platform critical.
Document WO 03/091102 discloses a platform, friction moved by a motor driver wheel, wherein the pallet should mount a height of about 25 millimeters.
Other documents, as for example, US 2012/0175170, disclose a platform with a greater thickness, moved by a belt transmission device.
Moreover, the distance between the base of the platform and the base of the pallet may make it difficult to transfer the rotating motion from the driving units to the pallet.
The aim of this invention is, therefore, to eliminate the above-mentioned disadvantages.
The invention, as characterised in the claims, achieves that aim thanks to a platform with reduced thickness, at least less than 24 millimeters and preferably less than 20.
The main advantage of this invention is basically the fact that the dimensions of the pallet up ramp are reduced as far as possible, in terms of both height and length.
Moreover, the transfer of the motion from the driving unit to the platform is simplified and allows a reduction in consumption, the power used being the same.
Finally, structural work is not used to make the platform.
As shown in the figures, the invention relates to a pallet wrapping platform, comprising a lower frame 1, a pallet supporting table 15, constraining means 4 interposed between the frame 1 and the table 15, being designed to allow the frame and table to move by rotating relative to one another, a driving unit 17 and transmission means 14 for transmitting the motion from the driving unit 17 to the table 15. The table 15 comprises an upper flat disk 15a and at least one lower crown wheel 15b, fixed to the disk 15a and designed to interact with the motion transmission means 14.
The join between the disk 15a and the crown wheel 15b is preferably made by welding, and in any case without the use of structural work, thereby allowing a total thickness s of the platform 10 which is less than 24 millimeters, and preferably comprised between 18 and 20 millimeters.
In the embodiment illustrated in the figures, the constraining means 4 comprise a central rotation device 41 and a peripheral rotation device 42. The central rotation device 41 comprises a plurality of bearings 5, 6, 9, designed to promote the movement of the table 15 relative to the frame 1. The peripheral rotation device 42 comprises a plurality of supporting units 11, distributed radially in seats 12 of the frame 1, being designed to promote the movement of the table 15 relative to the frame 1 and to give it resistance relative to the weight of the pallet. As shown in FIG. 4, each supporting unit 11 comprises a box-shaped body 11a, with dimensions matching those of the seats 12 of the frame 1, and at least one roller 11b, free to rotate relative to its own axis, housed in the box-shaped body 11a and slightly protruding from it. Each roller 11b comprises a core 11c made of highly rigid material, for example steel, in such a way as to provide suitable support for the table 15 above, and a cover 11d, preferably made of a plastic material commercially known as DERLIN®, suitable for limiting friction and noise.
In that embodiment, the motion transmission means 14 comprise a plurality of gear wheels 14a, 14b, 14c, which allow the motion to be transferred from the driving unit 17 to the table 15 supporting the pallet, interacting with the edge of the lower crown wheel 15b. 
The invention described above may be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all details of the invention may be substituted by technically equivalent elements.
Obviously, in practice modifications and/or improvements are possible, all covered by the claims herein.